* See warnings and precautions about use with antihypertensives and in patients with cardiovascular disease.

Drug Interactions

Viagra is a vasodilator and it is extensively metabolized by CYP3A4 and 2C9 liver enzymes. Therefore, combining Viagra with other vasodilators will increase the incidence of hypotension, and CYP3A4 or 2C9 inhibitors will increase the blood levels of Viagra.

Table 2. Viagra Drug Interactions

Drug

Effect

Recommendation

Nitrates for example, isosorbide, nitroglycerin

Increased hypotension

Contraindicated

Alpha adrenergic blockers

Increased hypotension

Caution. Patients should be stable on alpha blocker prior to Viagra administration and the lowest Viagra dose should be used

Efficacy of Viagra (sildenafil)

Lasts up to 4 hours and starts working within 30-60 minutes after administration.

In one study of patients with ED due to diabetes, psychogenic or mixed etiologies, Viagra 25, 50, and 100 mg resulted in 63%, 74%, and 82% of patients reporting improvement in erection, respectively. Only 24% of patients on placebo reported improvement in erection in the same study.

Cialis versus Viagra: Cialis can be administered daily, works within 15-30 minutes, and lasts 36 hours. Viagra works within 30-60 minutes and lasts about four hours.

Pharmacology (Mechanism of Action)

Viagra is a selective phosphodiesterase type 5 (PDE5) inhibitor. PDE5 is responsible for breaking down cyclic guanyl monophosphate (cGMP), a vasodilator produced in response to nitric oxide that is released due to sexual stimulation in the corpus cavernosum. Inhibition of PDE5 increases cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum, causing penile erection. Viagra works in response to sexual stimulation.

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Sex Problem In Men Sexual wellbeing is a significant part of a males life, no concern about his age, civil position, or sexual direction. It is also a significant fraction of a couple's base and adds to the excellence of life. Sexual issues in males can appear taboo but they are extremely general. We assist patients better comprehend the probable troubles influencing their sexual wellbeing and if feasible, to make them discuss them with their specialists.